Koko, the famous talking gorilla from Woodside who can communicate through sign language, had surgery for more than two hours on Sunday to heal a toothache, according to Stanford spokeswoman Sarah Sherwood.

After Koko continually complained about the aching tooth, her handlers at the Gorilla Foundation developed a pain chart and asked the 300-plus-pound primate to tell them on a scale of one to 10 how bad it hurt.

She gave it an eight.

"She's quite articulate," volunteer Johnpaul Slater told the Associated Press. "She'll tell us how bad she's feeling, how bad the pain is. It looked like it was time to do something."

While the world's first gorilla to use American Sign Language was sedated for the surgery, doctors took the opportunity to perform a full physical exam on the usually chatty animal.

Four hours and one tooth extraction later, she emerged healthy.

Koko, who celebrated her 33rd birthday on the Fourth of July, earned international fame for her 1,000-plus word vocabulary, which on Sunday included a request to meet her doctors before the anesthesia was administered.

A team of 12 specialists, including three dentists, a Stanford cardiologist, three anesthesiologists, an ear and throat specialist, two veterinarians, a gastroenterologist and a gynecologist, volunteered to do the exam -- for free -- on Koko's home turf in the Woodside hills.

"Koko's famous," said Dr. David Liang, assistant professor of medicine at Stanford. "It's not often that we get to work on a celebrity. Probably, Koko is less demanding."

Doctors gathered in Koko's "apartment" and crowded around the gorilla, who asked a woman wearing red to come closer. The woman politely offered Koko a business card, which the gorilla ate.

Approaching old age in gorilla years, the checkup was vital, as most captive gorillas only live to be in their 50s.

Koko's close friend Michael, also a member of the Gorilla Language Project, the longest continuous inter-species communications project of its kind in the world, died in 2000. Kubi, Koko's younger sister, died earlier this year after undergoing surgery to remove a lung.

Through Sunday's medical exam, doctors also were able to determine that Koko does not have any biological problems that would prevent her from having babies, something she and her longtime partner Ndume have been trying to do for years.